Motor vehicles are increasingly being equipped with sensors which monitor the surrounding environment. This sensor information may be used to more or less automatically control a future trajectory of the vehicle. This automation may range from a fully autonomous vehicle to a driver controlled vehicle where the sensor information is only used to inform the driver. In all levels of automation there is a need for safe driving, meaning in this case to plan and realize a vehicle trajectory with an acceptably low level of risk.
In a case where the automated function takes responsibility for a particular driving task, the automation system should be able to operate with a sufficiently low level of risk. This is the purpose of functional safety. This is challenging when the automation system uses sensors which have inherent limitations, e.g. cannot detect everything in the environment of the vehicle. This is why most automated functions rely on the fact that the driver of the vehicle is always responsible for safe operation of the vehicle and that the driver of the vehicle at any moment may regain control of the vehicle.
One such example is provided by document EP1990787 A1, which relates to properly dealing with a blocked area for which obstacle detection by an in-vehicle sensor cannot be performed. When there is a blocked area, for which a sensor mounted on an own vehicle cannot perform detection, in movable areas of the own vehicle, it is assumed that an obstacle can be present in the blocked area. When an obstacle can be present in the blocked area, unconfirmed bodies are arranged virtually in the blocked area as obstacle candidates. Thus, environmental prediction can be performed with the use of the obstacle candidates represented by the unconfirmed bodies. The behavior of an unconfirmed, virtual, moving body may be predicted, whereby an automobile model may be used for the prediction of a behavior of an automobile and a human model for the prediction of a behavior of a human, and further a single-moving-body model such as a two-wheeled motor vehicle model and a bicycle model as necessary. A predicting unit can predict a possibility of collision and the like of the own vehicle during driving by predicting a possible track based on the behaviors of the unconfirmed bodies that are arranged eventually in the movable areas of the own vehicle, and the behavior of the own vehicle (such as a speed and a steering direction), for example. In particular, even when there is the blocked area in the movable area, and detection by the sensor mounted on the own vehicle cannot be performed on the blocked area, it is assumed that there might be an obstacle in the blocked area, and when there can be an obstacle in the blocked area, the unconfirmed bodies are arranged virtually as the obstacle candidates in the blocked area. The obstacle detecting method, the obstacle detecting apparatus, and the standard moving-body model according to EP1990787 A1 are said to be useful for collision avoidance, collision warning, and the like of automobiles, and particularly suitable for automatic driving of automobiles.
According to document EP1990787 A1, unconfirmed moveable candidate objects are placed at all positions in all blocked areas where it is possible that a moveable object might exist. These candidate objects are later replaced by observed real objects once the area has been observed, alternatively the candidate objects are removed once the area has been observed. Candidate objects may e.g. be represented by pedestrians or vehicles. Replacing the candidate objects with real observed objects is said to enable use of improved prediction models for the observed objects as compared to the virtual candidate objects.
However, although document EP1990787 A1 relates to an obstacle detection method, it nowhere mentions how an associated vehicle should respond to the candidate objects. Thus, there is still room for improvement in the above field.